The invention is concerned with improvements in windshield wiper assemblies and, more particularly, with retention of the refill unit in the superstructure.
Windshield wipers for motor vehicles typically comprise a flexible or articulated superstructure which supports and distributes pressure along the length of a wiping element, often termed a "refill unit". The refill unit includes an elongate, stiff resilient backing strip which supports an elastomeric wiping element. A number of different means for retaining the blade unit in the superstructure have been commonly utilized. One of the most common means for retaining the refill unit against longitudinal displacement is a clip located at the end of the backing strip which engages a claw of the superstructure as shown in U.S. Pat. No. 3,253,254 to E. W. Lenz et al. Another retention means which comprises a notch in a widened portion of the packing strip is described in U.S. Pat. No. 3,141.186 to A. C. Scinta. U.S. Pat. No. 4,208,770 to W. D. Appel illustrates yet another retention means wherein the ends of the superstructure have depending abutments. The refill unit is slipped through a series of claws until one end of the backing strip engages an abutment at one end of the superstructure. Then either the superstructure or the refill unit is distorted so as to enable the other end of the refill unit to be positioned for engagement with an abutment at the opposite end. Various other forms of clips, abutments and notched elements are employed for retention purposes.